Ukraine's security council secretary doesn't rule out Russia using nuclear arms if facing 'catastrophic defeat'
Nothing can be ruled out if Russia finds itself on the verge "of a catastrophic defeat," including the use of tactical nuclear weapons by Moscow, Oleksandr Lytvynenko, the National Security and Defense Council secretary, said in an interview with The Times published on June 16.
https://kyivindependent.com/security-council-secretary-putin-nuclear-arms/